Clark, Wilfrid E. Le Gros, author
Quadrangle Books, 1971
Buku Teks
Plamenatz, John
Longman, 1991
Buku Teks
Maritain, Jacques
The University of Chicago Press, 1951
Buku Teks
Dorrestein, Renate
uitgeverij contact, 1995
Buku Teks
Nesturkh, M. F. (Mikhail Fedorovich), author
Progress Publishers, 1967
Buku Teks